Comments

[ghc-hetmet.git] / compiler / basicTypes / MkId.lhs

diff --git a/compiler/basicTypes/MkId.lhs b/compiler/basicTypes/MkId.lhs
index 6e7b0c0..b7c442b 100644 (file)
--- a/compiler/basicTypes/MkId.lhs
+++ b/compiler/basicTypes/MkId.lhs
@@ -218,10 +218,8 @@ It's a bit more complicated if the data instance is a GADT as well!
 
    data instance T [a] where
         T1 :: forall b. b -> T [Maybe b]
-Hence
-   Co7T a :: T [a] ~ :R7T a
 
-Now we want
+Hence we translate to
 
         -- Wrapper
   $WT1 :: forall b. b -> T [Maybe b]
@@ -231,6 +229,9 @@ Now we want
         -- Worker
   T1 :: forall c b. (c ~ Maybe b) => b -> :R7T c
 
+        -- Coercion from family type to representation type
+  Co7T a :: T [a] ~ :R7T a
+
 \begin{code}
 mkDataConIds :: Name -> Name -> DataCon -> DataConIds
 mkDataConIds wrap_name wkr_name data_con
@@ -920,11 +921,11 @@ unsafeCoerceId
     info = noCafIdInfo `setUnfoldingInfo` mkCompulsoryUnfolding rhs
            
 
-    ty  = mkForAllTys [openAlphaTyVar,openBetaTyVar]
-                      (mkFunTy openAlphaTy openBetaTy)
-    [x] = mkTemplateLocals [openAlphaTy]
-    rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $
-          Cast (Var x) (mkUnsafeCoercion openAlphaTy openBetaTy)
+    ty  = mkForAllTys [argAlphaTyVar,openBetaTyVar]
+                      (mkFunTy argAlphaTy openBetaTy)
+    [x] = mkTemplateLocals [argAlphaTy]
+    rhs = mkLams [argAlphaTyVar,openBetaTyVar,x] $
+          Cast (Var x) (mkUnsafeCoercion argAlphaTy openBetaTy)
 
 ------------------------------------------------
 nullAddrId :: Id